Method of authenticating digital-watermark pictures
US6418232B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1999 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Aug 26, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T1/0064
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An extraction process includes the steps of carrying out a geometric transformation on a picture being inspected to transform the size of the picture being inspected into a reduced scale of an original picture; creating a plurality of degraded original pictures with different types each obtained as a result of degradation of the original picture; creating a plurality of differential pictures by subtraction of the degraded original pictures with different types from the picture being inspected with a transformed size to cancel degradation components in the picture being inspected with a transformed size; and extracting the information corresponding to the authentication information.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.